Reactions in solar panels, catalytic converters, and other devices are governed by the quick motion of electrons. To capture the movement of these electrons, scientists use pulses of extremely high energy x-rays. The challenge is making the pulses short enough to get a good look at the electrons. Now, the shortest-ever pulses of hard x-rays were produced using two methods developed at SLAC’s Linac Coherent Light Source. The pulse duration is just a few hundred attoseconds long, or billionths of a billionth of a second. It set a record for hard x-rays produced by free-electron lasers.